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F(x)=x^(3)+10x^(2)+33x+36

factor completley with work please

User Avf
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1 Answer

6 votes

Answer:


\sf f(x) = (x + 3)(x + 3)(x + 4)

Explanation:

To factor the cubic polynomial
\sf f(x) = x^3 + 10x^2 + 33x + 36, we can use various methods.

In this case, I'll use synthetic division to find one factor and then factorize the quadratic remaining.

1. First, we can try to find a root by testing potential factors of the constant term (36) divided by potential factors of the leading coefficient (1).

Let's try
\sf x = -1 because it often makes calculations easier.

Synthetic Division:


\sf \begin{array}c -1 & 1 & 10 & 33 & 36 \\ & \downarrow & -1 & -9 & -24 \\ \hline & 1 & 9 & 24 & 12 \\\end{array}

The remainder is 12, not 0.

So,
\sf x = -1 is not a root.

2. Next, let's try
\sf x = -2:


\sf \begin{array}c -2 & 1 & 10 & 33 & 36 \\ & \downarrow & -2 & -16 & 6 \\ \hline & 1 & 8 & 17 & 42 \\ \end{array}

Again, the remainder is not 0.

3. Let's try
\sf x = -3:


\sf \begin{array}c -3 & 1 & 10 & 33 & 36 \\ & \downarrow & -3 & -21 & -36 \\ \hline & 1 & 7 & 12 & 0 \\ \end{array}

We find that
\sf x = -3 is a root because the remainder is 0.

4. Now, we can factor the polynomial as
\sf f(x) = (x + 3)(x^2 + 7x + 12).

5. Further factor the quadratic term
\sf x^2 + 7x + 12 by factoring it into:


\sf x^2 + (4+3)x + 12


\sf x^2 + 4x + 3x + 12


\sf x(x+4)+3(x+4)


\sf (x+4)(x-3)


\sf (x + 3)(x + 4).

So, the completely factored form of
\sf f(x) is
\sf f(x) = (x + 3)(x + 3)(x + 4).

User Gordon Slysz
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